5Series.net - Forums - 6th gear acceleration flat spot 2009 E61 525d

Hi all,

My current 2009 525d touring with a manual gearbox is having a small issue when running at about 1500rpm in 6th Gear and wondered if anyone else has had the same problem and fixed it.

If i travel on a motorway at 50mph in 6th gear and want to accelerate i get a rumble from the engine but very slow acceleration. This rumble is not like any other acceleration noise in any other gear as they are smooth and fairly quiet. This rumble is like the car is misfiring at speed and shaking the car. Now this only seems to happen in 6th gear and when its below 2000rpm.

If anyone has experienced this and has had the issue solved or has any ideas i would love to here them as i know when i owned a 330d E46 if i was in 6th gear i could accelerate on motorways smoothly without any issues. I think they will be roughly the same engine so should have some similar characteristics.

The car pulls very well in all other gears and seems to be very good on juice with me getting around 50mpg on a run and 35-45mpg on normal daily driving.

I have also checked on a snap-on diagnostics machine my friend has with no error codes within the system.

Any help is very much appreciated.